Estimates were made for the future uptake of excess CO2 across the air/sea interface. If CO2 emissions continue to rise as predicted in a moderate growth scenario, surface ocean inorganic carbon concentrations could rise as much as 400 mu mol kg(-1) (20%) over the next 300 years. Increases in CO2 uptake of this magnitude may have a significant impact on the surface ocean ecosystem. Furthermore, these high atmospheric and surface ocean concentrations of CO2 will significantly reduce the effectiveness of CO2 ocean storage, particularly for shallow depth discharges.